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HKDSE Biology - Photosynthesis and Respiration 

Compulsory Part I Cells and Molecules of Life

May 5, 2020
  • Compare the processes of respiration and photosynthesis.
  • Be aware of the interconversions of biomolecules through biochemical pathways.

Comparison between Photosynthesis and Respiration 

👆🏻This photo showing the interactions between photosynthesis and respiration.

In HKDSE Biology examination, it is common to ask students to compare photosynthesis and respiration in essay type question ❗️ ❕

1. Occurrence 

  • Photosynthesis - 
  • plants, algae as well as photosynthetic bacteria.
  • Respiration - 
  • ALL organisms.

2. Function

  • Photosynthesis - Conversion of 
  • light energy from the sun to chemical energy and further stored in glucose.
  • Respiration - Release of 

chemical energy in glucose to generate ATP which is energy utilized by the cell.

3. Reactants

  • Photosynthesis - 
  • Carbon dioxide, water and light energy.
  • Respiration - 

Glucose and oxygen.

4. Metabolic process

  • Photosynthesis - 
  • Anabolism.
  • Glucose molecules are produced from carbon dioxide, ATP and NADPH.
  • Respiration - 
  • Catabolism.
  • Carbon dioxide, ATP, NADH and FADH

2 are produced from the break down of glucose.

5. Location 

  • Photosynthesis - 

Chloroplast.

  • Respiration - 

Cytoplasm and mitochondria.

6. Energy source

  • Photosynthesis - 

Sunlight ☀️

  • Respiration - 

Glucose.

7. Stages

  • Photosynthesis - 

Photochemical reaction and Calvin cycle.

  • Respiration - 

Glycolysis, Krebs cycle and Oxidation phosphorylation.

👆🏻This photo showing the relation among photosynthesis and respiration.

Photosynthesis generates glucose and oxygen which are used in respiration.

Respiration generates carbon dioxide which is used in photosynthesis.

That's the end of this topic 👏🏻

 

  1. References 
  2. Photosynthesis and Respiration

. Photosynthesis Education. https://photosynthesiseducation.com/photosynthesis-and-cellular-respiration/.